Perennial (or annual?), sometimes with a definite base and tuberous roots or, more commonly, without a base, and with fibrous roots only; shoots ascending to decumbent and rooting at the nodes, often forming cleistogamous flowers on short, subterranean shoots from the rooted nodes. Leaves distichous, sheaths c. 0.5–1.3 cm long, puberulous, sometimes with a line of longer hairs along the fused edge, ciliate at the apex, blade elliptic to linear-lanceolate, flat to conduplicate, 1.5–6(–7) x 0.4–1.2(–2) cm, apex acute to rounded, often mucronulate and recurved, base oblique, cuneate, surfaces puberulous or pilose-puberulous or the upper sometimes subglabrous, margins strongly undulate. Spathes solitary on 0.4–1.3 cm long peduncles with a line of pubescence, not falcate, 0.8–1.5 x 0.45–0.8 cm, hirsute-puberulous, margins fused basally, glabrous, often violet; upper cincinnus usually well­developed, exserted, 1-flowered, lower 2–3-flowered. Flowers bisexual and male, c. 1.5 cm wide; paired sepals shortly fused basally or ± free; petals dark blue, the lower one very reduced and lanceolate or subulate; lateral stamens with lyrate, winged filaments, anthers blue, medial stamen with larger saddle-shaped, blue or blue-violet connective with yellow, sterile basal lobes. Capsules obovoid, 6–6.5 x 4–4.5 mm when seeds of ventral cells developed, 3.5–4 x 2–2.5 mm when only dorsal cell developed, dorsal cell indehiscent, keeled on the back and with low, longitudinal, crenate ridges or rows of tubercles, 1-seeded, ventral cells usually abortive, occasionally the apical seed developed. Seeds of ventral cells, when present, transversely elliptic to broadly ovate, c. 2.5–3 x 2 mm, testa brown, smooth, farinose.